Working on materials that must remain super clean, such as for example solid state electronics, requires an unquestionably pure atmosphere. Manufacturers of such components employ large clean rooms to assure the quality of their products. However, the entrance of a person into such clean rooms involves an extensive cleaning and dressing process that may consume at least 45 minutes before entering the room and another 45 minutes after departing the room. A clean box allows experimentation with materials on a much smaller scale and, at the same time, dispenses with the need for the extensive peripheral activity prior to entering and after departing the clean area.
Thus, clean boxes find a variety of uses including experimentation on materials and as incubators. In essence, the boxes provide a purified atmosphere and permit the entrance of a person's arms or other body parts in a fashion that allow him to work on items inside without introducing extraneous, contaminating matter. For example, the box may include rubberized, long gloves sealed to a side to prevent external air from entering the box. Yet, the operator, by placing his hands and arms in the gloves, can work upon material or even an infant lying inside the box. Yet, the gloves, formed of an air-impermeable material and having an air-tight seal to the remainder of the box, do not permit the passage of contaminants to the box's interior.
However, the boxes must have a sufficient size to hold the various components that might find use in an experiment or to contain an infant and the associated equipment and monitors. The problem then develops that a pair of rubberized gloves in a box of even minimally useful size cannot reach all areas on the box's interior. Thus, even though the box may contain important items, an operator's hands in the usual pair of gloves cannot reach all the components that he may desire. Further, the gloves display substantial stiffness to make sure that they do not allow for the penetration of outside, nonpurified air. This stiffness exacerbates this limited range of reach.
Manufacturers of clean boxes have attempted to ameliorate the problem of the operator lacking the ability to reach all areas on the interior in several fashions. Some boxes, for example, place three openings, each with a separate glove, along one side. The operator may select which adjoining two of the three openings to place his arms into. To reach an area that his initial selection would not permit, he simply removes his arms from the two openings, moves slightly to the side, inserts his hands through two gloves, including one not previously used, and achieves a reach over an area not previously accessible. While this increases the area of coverage inside a clean box, it still has undesirable drawbacks. Initially, the operator must take his hands off an item that he previously held. Furthermore, the presence of three, as opposed to two, rubberized gloves, portends the greater likelihood of leaks developing with a concomitant introduction of unpurified air. Furthermore, the added equipment naturally increases the cost of the unit. And, the third glove may prove an encumbrance when not in use.
For relatively large clean boxes, one manufacture has used a rubberized, transparent, sheet of material that actually covers the upper portion of an operator's body. This allows him, from the waist up for examples, to actually enter the clean box from below and achieve some degree of movement. Again, however, this represents an extremely expensive manner in which to achieve accessibility over a greater area throughout the clean box. Furthermore, such a large sheet of material has an ever, greater likelihood of developing undesired leaks. Moreover, since the operator enters the upperbody sheet of material from the bottom, a large portion of the dry box's volume goes to accommodate the operator rather then the material contained inside. As a consequence, the search continues for a clean box having increased accessibility throughout its volume.